Internal combustion engine having exhaust gas bypassing control mechanism

ABSTRACT

[PROBLEMS] To provide an internal combustion engine enabling an increase in engine efficiency and fuel economy and a reduction in residual black smoke concentration of exhaust gas. [MEANS FOR SOLVING PROBLEMS] One end of each of air flow passages is connected to the side wall of the cylinder exhaust tube of each of cylinders, the other end of each of these air flow passages is connected to a shared bypass control chamber, and the exhaust tube of each of the cylinders is connected to each of the flow passages through the shared bypass control chamber. Thus, a part of pressurized exhaust gas in the exhaust tube of each of the cylinders brought in an exhaust step when the other cylinders are in an explosive step is discharged to the bypass control chamber through the air flow passage by the compression explosion compressive pressure of the atmosphere produced as a reaction immediately after an explosion exhaust to absorb an exhaust resistance. On the AS other hand, a part of a surplus pressure gas in the bypass control chamber is sent to the other cylinder exhaust tubes through the other air flow passages, and a fuel and an air in the exhaust gas are uniformly mixed with each other in an entire bypass step and re-burned for complete combustion.

TECHNICAL FIELD

The present invention concerns an improvement for an internal combustion engine such as a diesel engine, a gasoline engine, or a gas engine having a plurality of cylinders, and it particularly relates to an internal combustion engine of making discharge of a combustion exhaust gas smooth to improve the engine efficiency and drastically decreasing a residual black smoke concentration in an exhaust gas.

BACKGROUND ART

Internal combustion engines having a plurality of cylinders and utilizing an explosive force of a fuel in the cylinders have been generally used long since as engines for diesel cars, gasoline cars and propane cars. In the internal combustion engines of this type, independent cylinder exhaust tubes disposed to respective cylinders are in communication with a common exhaust discharge cylinder and extended backward to a vehicle and explosion exhaust gases discharged successively from each of the cylinders at a predetermined time lag are discharged in atmospheric air.

DISCLOSURE OF THE INVENTION Subject to be Solved by the Invention

In this case, when an explosive exhaust gas of a fuel discharged to each of cylinder exhaust tubes is jetted from an exhaust cylinder by a strong explosive pressure, surrounding atmospheric air is rapidly compressed to the center by implosion just after the explosive jetting by the reaction thereof and a pressurized gas backflows into the exhaust cylinder under the effect thereof to increase the exhaust resistance of the cylinder exhaust tube during exhaustion, which interferes smooth operation of the engine. Therefore, this causes a problem for the engine efficiency such as undergoing restriction to the number of rotation per unit time.

Particularly, in a diesel engine, since the fuel compression ratio is high and the explosive force is strong, the effect of implosion is larger and it is limited utmost to about 3000 rotation/min in usual running.

The “implosion” means a phenomenon that a fluid expanded just after the extrusion of the fluid to the outside by explosion is shrunk all at once (explosively) to an original area as a reaction thereof.

On the other hand, an internal combustion engine sometimes releases a great amount of noxious gases such as black smoke due to incomplete combustion of a fuel. Particularly, in diesel engines, discharge of the black smoke or Nox causes a social problem in view of environmental contamination.

Accordingly, a first object of the present invention is to improve an engine efficiency by suppressing exhaust interference due to implosion caused as a reaction of the jetting of an exhaust gas.

A second object of the invention is to bypass a portion of an incomplete combustion exhaust gas jetted to a high pressure cylinder exhaust tube to other cylinder exhaust tube under the state of a low pressure and burn the same by a high temperature exhaust gas upon next explosion, and burn air and fuel in a uniformly mixed state in the course of bypassing, thereby suppressing release of incomplete combustion exhaust gas such as a black smoke.

A third object of the invention is to improve the fuel cost, particularly, in a diesel engine.

Other object of the invention is to decrease the nitrogen oxide (Nox) in an exhaust gas.

Means for the Solution of the Subject

For attaining the first to the third objects simultaneously, the internal combustion engine of the invention includes a constitution having a plurality of engine cylinders for piston operation at a predetermined time lag and a common exhaust gas cylinder in communication with exhaust tube for each of engine cylinders, in which one end of an air flow passage is in communication with the cylinder exhaust tube of each cylinder of an engine main body, the other end of each air flow passage is in communication with a common bypassing control chamber, the cylinder exhaust gas tubes are in communication to each other by way each of the air flow passages and the common bypassing control chamber whereby, by the implosion compressive pressure of atmospheric air from an exhaust gas tube caused as reaction just after the explosive exhaustion, a portion of a pressurized exhaust gas in a cylinder exhaust gas tube which is in an exhaustion step upon explosive step of other cylinders is delivered by way of the air flow passage to the bypassing control chamber, and a portion of a surplus pressurized gas in the bypassing control chamber is sent by way of other air flow passage to the cylinder exhaust tube under the state of a low pressure.

Preferably, in the manufacture of an internal combustion engine of the invention, each of the cylinder exhaust tubes in communication with each of the cylinder exhaust ports of the engine main body, the air flow passage branched from each of the exhaust tubes, the common bypassing control chamber in communication with each of the air flow passages, and a common exhaust cylinder connection port in communication with each of the cylinder exhaust tubes are formed integrally in a casing, and each of the cylinder exhaust tubes and each of the cylinder exhaust ports of the casing may be combined so as to be in communication with the engine main body.

An air injection means having a check valve may be disposed to the bypassing control chamber and oxygen may be supplied to an exhaust gas in the bypassing control chamber.

For attaining other object, an alkali ingredient injection means having a check valve may be disposed to the bypassing control chamber so as to remove nitrogen oxide in the exhaust gas with the alkali ingredient.

Effect of the Invention

In the internal combustion engine of the invention, just after the jetting of an explosive exhaust gas, when a compressed gas caused by the implosion of a gas at the periphery of the exhaust cylinder exhaust port enters the cylinder exhaust tube during exhaustion, a portion of the exhaust gas of the cylinder exhaust tube undergoing the resistive pressure flows through the air flow passage to the common bypassing control chamber. Therefore, since the exhaust gas of the exhaust tube does not undergo the resistance of the implosion and is discharged smoothly, the engine rotation speed increases. As a result, the engine efficiency such as increase in the vehicle speed and improvement in the fuel cost is enhanced remarkably, as well as vibrations of a muffler or the exhaust tube due to jetting and implosion is suppressed.

On the other hand, a portion of the exhaust gas in the bypassing control chamber that receives a portion of the exhaust gas of the jetting cylinder exhaust tube is bypassed by the pressure increase to a low pressure cylinder exhaust tube at the instance and stays therein. In a case of incomplete combustion of the exhaust gas, when the exhaust gas at high temperature and high pressure is jetted in the next step to the cylinder exhaust tube, since the stagnating exhaust gas is burnt again and discharged by the heat of the exhaust gas at high temperature and high pressure, discharge of black smoke due to incomplete combustion is decreased.

In each of the cylinders of the engine, a fuel suction step, a compressive step, an explosion step, and an exhausting step are successively conducted instantaneously and continuously at a time interval. The black smoke is caused mainly by mixing failure of air and fuel. In the invention, since a bypassing exhaust gas circulating through the cylinder exhaust tube, the air flow passage, and the bypass control chamber flows continuously at a high speed while changing the route, air and fuel in the incomplete combustion gas are mixed uniformly in the bypassing process. Accordingly, since the factor for the incomplete combustion is removed from the exhaust gas bypassed from the bypassing control chamber to the cylinder exhaust tube and the black smoke is not generated, this provides a double effect being coupled with the suppression of the exhaust gas resistance.

Further, in a case of providing the air injection means to the bypassing control chamber, oxygen is supplied to the exhaust gas to further improve incomplete combustion.

Further, in a case of providing the alkali ingredient addition means to the bypassing control chamber, Nox in the exhaust gas is neutralized when the exhaust gas is completely burnt at a high temperature to improve the Nox content in the exhaust gas.

While the invention is applicable to any of internal combustion engines such as a diesel engine, a gasoline engine, and a gas engine, a remarkable improvement in the engine efficiency can be obtained particularly in a case when it is used for the diesel engine.

BEST MODE FOR CARRYING OUT THE INVENTION

Examples of the invention are to be described with reference to the drawings.

FIG. 1 shows a schematic constitution of an internal combustion engine 1 in which the invention is applied to an engine of a vehicle and, in the internal combustion engine 1, there is shown an example of an engine main body 2 of a four cylinder engine having cylinders 2 a, 2 b, 2 c, and 2 d for conducting engine steps of fuel suction, compression, explosion, and exhaustion at a predetermined time difference.

While not illustrated, a piston is inserted reciprocally and slidingly in the direction of an inner axis to each of the cylinders 2 a, 2 b, 2 c, and 2 d. The top end of the piston is connected with an engine crankshaft to rotate the engine crankshaft by the reciprocal movement of the piston for each of the cylinders that cause explosion at a time difference to obtain a predetermined power.

Each of the cylinders 2 a, 2 b, 2 c, and 2 d of the engine main body 2 has its own cylinder exhaust tubes 3 a, 3 b, 3 c, and 3 d, and the cylinder exhaust tubes 3 a, 3 b, 3 c and 3 d are in communication with a common exhaust cylinder 4 that extends backward to a vehicle (not illustrate), and explosive combustion exhaust gas of each of the cylinder exhaust tubes 3 a, 3 b, 3 c, and 3 d is sequentially discharged to atmospheric air in a jetting manner (refer to outward arrow).

Reference numeral 5 denotes a muffler.

In the internal combustion engine described above according to the invention, one end of each of fine air flow passages 6 a, 6 b, 6 c, and 6 d is in communication with the inside on the side wall near the exhaust port of the cylinder exhaust tubes 3 a, 3 b, 3 c, and 3 d of each of the cylinders 2 a, 2 b, 2 c and 2 d of the engine main body 2, and each of the other ends of the air flow passages 6 a, 6 b, 6 c, and 6 d is in communication with a separately disposed common bypassing control chamber 7.

The inner diameter for the air flow passages 6 a, 6 b, 6 c, and 6 d is preferably about from ⅓ to ⅔ of the inner diameter of the cylinder exhaust tubes 3 a, 3 b, 3 c, and 3 d. In a case where it is excessively fine, passage of the air flow passage is worsened and in a case where it is excessively large, the balance of the exhaust gas, etc. are worsened. Further, in the example of FIG. 1, the air flow passages 6 a, 6 b, 6 c, and 6 d are preferably stainless tubes and both ends are fixed to the side wall of each of the cylinder exhaust tubes 3 a, 3 b, 3 c, and 3 d and the wall of the bypassing chamber 7.

Thus, each of the cylinder exhaust tubes 3 a, 3 b, 3 c, and 3 d is in communication to each other by way of the air flow passages 6 a, 6 b, 6 c, and 6 d of its own and the bypassing control chamber 7.

FIG. 2 and FIG. 3 show another example of the invention. In this example, the cylinder exhaust tubes 3 a, 3 b, 3 c, and 3 d, air flow passages 6 a, 6 b, 6 c, and 6 d branched respectively from the exhaust tubes 3 a, 3 b, 3 c, and 3 d, the common bypassing control chamber 7, and the exhaust port 11 of the discharge cylinder 4 in communication with each of the exhaust tubes 3 a, 3 b, 3 c, and 3 d are assembled in a common casing 10. The casing 10 is integrally joined with the engine main body 2 such that each of the cylinders 2 a, 2 b, 2 c, and 2 d is in communication with each of the cylinder exhaust tubes 3 a, 3 b, 3 c, and 3 d, and each of the cylinder exhaust tubes 3 a, 3 b, 3 c, and 3 d is in communication to each other by way of the air flow passages 6 a, 6 b, 6 c, and 6 d, and the common bypassing control chamber 7.

The example of FIG. 2 and FIG. 3 is a modified example of the example in FIG. 1 and it has an advantage in view of manufacture in that the number of parts can be saved and it can be integrally attached in a compact manner to the engine main body 2, although they are in common in view of the theory, the technical idea and the function and the effect of the invention.

In FIG. 2 and FIG. 3, a solid arrow shows the flow of the explosive exhaust gas and the dotted arrow shows the flow of a gas by implosion and they schematically show that suction, compression, explosion, and exhaustion of a plurality of gases are continuously conducted instantaneously.

Then, the operation of the internal combustion engine of the invention is to be described.

When the engine main body 2 is started, a fuel is exploded successively in the inside of each of the cylinders 2 a, 2 b, 2 c, and 2 d with a time difference, the exhaust gas is jetted in an explosive manner successively from each of the cylinder exhaust tubes 3 a, 3 b, 3 c, and 3 d and released from the exhaust cylinder 4 to the atmospheric air. When the exhaust gas is explosively released as described above, an external gas forcively expanded by the exhaust gas is instantaneously put to implosion just thereafter by the reaction of explosion, the pressure caused by the implosive compression exerts on the exhaust cylinder 4 (refer to inward arrow) and acts as a resistive force to the discharge of the release gas. Accordingly, since the phenomenon occurs continuously along with the explosion in each of the cylinders 2 a, 2 b, 2 c, and 2 d in the existent internal combustion engine, the exhaust gas flows out smoothly. Accordingly, wasteful load exerts on the engine, to results in a major factor of restricting the number of rotation/time and a factor of violent vibrations of the exhaust tube or the muffler in a minute amplitude by the succession of instantaneous explosion and implosion.

In the invention, since each of the cylinder exhaust tubes 3 a, 3 b, 3 c, and 3 d and air flow passages 6 a, 6 b, 6 c, and 6 d are in communication to the bypassing control chamber 7, when the compression gas enters to the exhaust cylinder 4 by the implosion of the atmospheric air to increase the inner pressure of the engine cylinder 2 a for example, just after the explosive jetting of the exhaust gas from the engine cylinder 2 a, a portion of the pressurized gas in the cylinder exhaust tube 3 a flows instantaneously by way of the air flow passage 6 a to the bypassing control chamber 7 to absorb the pressure in the exhaust cylinder 4. Also in a case where the explosion jetting step transfers to other cylinder exhaust tube 3 b, 3 c, or 3 d, the pressurized exhaust gas flows in the same manner from the air flow passage 6 b, 6 c, or 6 d to the bypassing control chamber 7 to absorb the pressure in the exhaust cylinder 4.

Thus, since the resistance due to the implosion is not caused to the cylinder exhaust tube and the exhaust cylinder 4, exhaust gas in each of the cylinder exhaust tubes 3 a, 3 b, 3 c, and 3 d is discharged smoothly to increase the number of rotation of the engine and enhance the engine efficiency.

On the other hand, when the exhaust gas of the cylinder exhaust tube 3 a flows to the bypassing control chamber 7 in a state where the internal pressure of the bypassing control chamber 7 is high, a portion of the exhaust gas in the bypassing control chamber 7 is sent out to other cylinder exhaust tubes 3 b, 3 c or 3 d in a low pressure state (for example, suction step).

In a case where the exhaust gas bypassed from the bypassing control chamber 7 by way of the air flow passage to the cylinder exhaust tube is not yet burnt completely, when the combustion exhaust gas is jetted from the cylinder exhaust tube as the destination of bypassing the exhaust gas, the incomplete combustion gas flowing out there by way of the air flow passage is burnt again at a high temperature of the jetted gas and discharged from the exhaust cylinder 4. Accordingly, discharge of noxious substances such as the black smoke is suppressed by complete combustion or re-combustion of the exhaust gas. In this case, the exhaust gas flowing from the cylinder exhaust tube into the bypassing control chamber 7 and supplied from the bypassing control chamber 7 to each of the cylinder exhaust tubes is completely burnt since the air and the fuel are mixed uniformly in the course of the bypassing to eliminate generation of the black smoke.

FIG. 4 shows a further example of the invention. In the example, an air (oxygen) injection means 9 having a check valve 8 that opens to the side of the control chamber is disposed in the bypassing control chamber 7. Accordingly, by the supply of oxygen to the exhaust gas in the bypassing control chamber 7, complete combustion of the exhaust gas bypassed through the air flow passage is conducted more efficiently.

As shown in FIG. 5, when the fuel is put to complete combustion and discharged at a high temperature, when an alkali ingredient such as sodium hydrogen carbonate is added from an alkali ingredient injection means 12 to the bypassing control chamber 7, Nox is removed by neutralization.

Description is to be made for the performance and the engine efficiency in a case of applying the invention to a vehicle engine.

EXPERIMENTAL EXAMPLE 1

Car as an object of experiment: Diesel passenger car

Type of car: “Bluebird” (trade mark) manufactured by Nissan Motor Co. Ltd. in 1992

Engine mounted: 4-cycle 4-cylinder diesel engine

Total engine displacement: 1973 cc

Engine power: 4800 rpm/min, 76 Hp (in the state of new car)

Fuel cost (heavy oil): about 12 km/liter

Residual diesel black smoke concentration in exhaust gas: 55%

Vibration of exhaust cylinder: Violent vertical and lateral vibrations were observed.

An air flow passage made of stainless steel with an inner diameter of ⅓ of the inner diameter for an exhaust tube was in communication with each of the cylinder exhaust tubes of the diesel passenger car and the other end of each of the air flow passages was in communication with the tightly closed hollow bypassing control chamber disposed separately to a frame near the engine to modify into a structure of the internal combustion engine of the example shown in FIG. 1.

The result of a running experiment for the modified car is as follows.

Engine power: 5500 rpm/min

Fuel cost (heavy oil): about 16 km/liter

Residual diesel black smoke concentration in exhaust gas: 3% or less (not detectable for 3% or less)

Vibration of exhaust cylinder: Existent violent vibrations were scarcely observed.

In the modified engine described above, discharge of the black smoke inherent to the diesel engine from the exhaust cylinder was not observed even at the start of the modified engine, and the exhaust gas was of a color thinner than that of a gasoline car.

While the running test up to the limit was not conducted since danger might be expected but 180 km per hour of speed was expected and it gave a feeling of an engine of extraneous nature superior to gasoline engines.

INDUSTRIAL APPLICABILITY

The internal combustion engine of the invention is remarkably improved for the engine power, speed, and the fuel cost, the engine efficiency is improved, complete combustion is promoted, and discharge of noxious substances is improved.

Particularly, the effect is remarkable when applied to a diesel engine and this can contribute to the increase of the engine efficiency and the regulation of exhaust gas of diesel cars.

BRIEF DESCRIPTION OF THE DRAWINGS

[FIG. 1] is a schematic constitutional view of an internal combustion engine according to an example of the invention.

[FIG. 2] is a schematic constitutional view of an internal combustion engine according to another example of the invention (longitudinal cross sectional view).

[FIG. 3] is a cross sectional view along A-A in the example shown in FIG. 2.

[FIG. 4] is a schematic constitutional view of an internal combustion engine according to a further example of the invention.

[FIG. 5] is a schematic constitutional view of an internal combustion engine according to a further example of the invention.

DESCRIPTION OF REFERENCE NUMERALS

-   1 . . . Internal combustion engine -   2 . . . Engine main body -   2 a, 2 b, 2 c, 2 d . . . Cylinder -   3 a, 3 b, 3 c, 3 d . . . Cylinder exhaust tube -   4 . . . Exhaust cylinder -   5 . . . Muffler -   6 a, 6 b, 6 c, 6 d . . . Air flow passage -   7 . . . Bypassing control chamber -   8 . . . Check valve -   9 . . . Air injection means -   10 . . . Casing -   11 . . . Exhaust port -   12 . . . Alkali ingredient injection means 

1. An internal combustion engine having a plurality of engine cylinders conducting piston operation at a predetermined time lag and a common exhaust cylinder in communication with an exhaust tube for each of the engine cylinders, in which one end of an air flow passage is in communication with a cylinder exhaust tube for each of the cylinders of an engine main body, the other end of each of the air flow passages is in communication with a common bypassing control chamber, the cylinder exhaust tubes are in communication to each other by way of each of the air flow passages and the common bypassing control chamber, whereby an implosive compression pressure of an atmospheric air from the exhaust cylinder generated as reaction just after the explosive exhaustion delivers, a portion of a pressurized exhaust gas in the cylinder exhaust tube that conducts an exhaustion step during the explosive step of other cylinder by way of the air flow passage to the bypassing control chamber, and a portion of a surplus pressure gas in the bypassing control chamber is sent out by way of other air flow passage to a cylinder exhaust tube under the state of a low pressure.
 2. An internal combustion engine according to claim 1, wherein each of the cylinder exhaust tubes in communication with each of the cylinder exhaust ports of the engine main body, an air flow passage branched from each of the exhaust tubes, a common bypassing control chamber in communication with each of the air flow passages, and a common exhaust cylinder connection port in communication with each of the cylinder exhaust tubes are formed in an integral casing, and they are joined to the engine main body such that each of the cylinder exhaust tubes and each of the cylinder exhaust ports are in communication with each other.
 3. An internal combustion engine according to claim 1, wherein an air injection means having a check valve that opens to the side of the control chamber is disposed to the common bypassing control chamber.
 4. An internal combustion engine according to claim 1, wherein an alkali ingredient injection means having a check valve that opens to the side of the control chamber is disposed to the common bypassing control chamber.
 5. An internal combustion engine according to claim 2, wherein an air injection means having a check valve that opens to the side of the control chamber is disposed to the common bypassing control chamber.
 6. An internal combustion engine according to claim 2, wherein an alkali ingredient injection means having a check valve that opens to the side of the control chamber is disposed to the common bypassing control chamber.
 7. An internal combustion engine according to claim 3, wherein an alkali ingredient injection means having a check valve that opens to the side of the control chamber is disposed to the common bypassing control chamber. 